Project Summary Urolithiasis is a disease that affects 12% of the population and its incidence is growing. In the US there are over 1.1 million visits annually to Emergency Departments for renal colic. The disease is extremely painful, often requiring large amounts of narcotic analgesia, and results in lost work days. Moreover, up to 30% of patients may eventually require lithotripsy or surgical removal of the stone. Currently there are no medical interventions other than analgesia which are offered to patients. Based on encouraging results from several small European clinical studies, it appears that the administration of tamsulosin to patients with symptomatic urolithiasis enhances stone passage, and reduces both the time to recovery and the need for surgical intervention or lithotripsy. A pilot study was carried out at The George Washington University that enrolled 109 patients. This study demonstrated that we could enroll patients in the setting of the emergency department, and achieve high rates of follow-up. In order to determine the efficacy of tamsulosin we need to enroll approximately 500 patients, and in order to do this we plan a multicenter study. This Planning grant will be used to plan and prepare for the multicenter study, During the planning phase the following steps will be completed: a) Finalize final study protocol;b) Finalize manual of procedures;c) Develop consent forms;d) Develop and the test on-line data entry tool;e) Develop the data monitoring and management plan;f) Develop a plan for the acquisition and administration of study drug &placebo;g) Develop a safety oversight plan;h) Develop a detailed budget for conduct and completion of the clinical trial;i) Develop training materials and training for study staff;j) Initiate training of study coordinators at new clinical study sites;k) Submit for IRB approval;l) Initiate training of all ED clinical staff at new clinical study sites m) Submission of the U01 multicenter study proposal. If we can study the therapeutic benefit of tamsulosin, it will represent a major advance in the treatment of urolithiasis. This objective is a major stated goal of the NIDDK Clinical Urology Program, which has a stated mission to improve the treatment of urolithiasis. PUBLIC HEALTH RELEVANCE: Project Narrative This grant will support the planning of a multicenter study to test if tamsulosin helps patients with painful kidney stones. There is no current medical treatment for kidney stones, but some small trials have shown a benefit from tamsulosin. We will plan a large clinical trial that can determine if there is indeed any benefit from this medicine to treat this painful condition, a condition that sends over one million people to the emergency department each year.